Technique of interventional repair in adult aortic coarctation

Intraventricular haemodynamic changes caused by increased left ventricular afterload in re-coarctation of aorta: a case report

Background

Long-term re-coarctation of the aorta can cause aortic dilatation, hypertension, and cardiac dysfunction due to increased left ventricular (LV) afterload. It is difficult to detect changes in LV function due to increased afterload if the contractile force of the left ventricle is maintained. Herein, we have reported a case of re-coarctation of the aorta, for which four-dimensional (4D) flow magnetic resonance imaging (MRI) scan was obtained both before and after balloon dilatation for aortic re-coarctation. Ultimately, improvement in aortic helical flow and LV haemodynamics was observed.

Case summary

A 29-year-old female was diagnosed with coarctation of the aorta and a bicuspid aortic valve after birth and underwent surgery at 1 month. At 8 years of age, she underwent balloon dilatation for re-coarctation. At the age of 28 years, she was diagnosed with re-coarctation triggered by hypertension. She underwent balloon dilatation as her cardiac catheterization revealed a systolic pressure gradient of 40 mmHg. Pretreatment 4D flow MRI demonstrated helical flow in the ascending aorta and descending thoracic aorta and LV blood flow analysis revealed a decrease in LV kinetic energy during systole; these improved after treatment.

Discussion

The use of helical flow evaluation by 4D flow MRI for aortic re-coarctation is well known in clinical practice. However, our report is the first to evaluate intraventricular blood flow before and after the re-coarctation treatment. The MRI evaluation demonstrated that the helical flow and LV blood flow distribution improved after re-coarctation treatment due to the reduction of afterload.

Myelopathy in adult aortic coarctation: Causes and caveats of an atypical presentation

A 57-year-old female presenting with acute-onset paraplegia was referred for magnetic resonance imaging (MRI) of cervico-dorsal spine. On MRI, multiple tortuous dilated vessels were noted in the epidural space with long segment cord compression and imaging features of compressive myelopathy. Associated small acute cervico-dorsal epidural hematoma was also noted in the same region. Computed tomography (CT) angiography was performed subsequently which revealed post-ductal coarctation of aorta with multiple arterial collaterals in the chest wall and spinal canal. An extensive review of English language literature pertaining to the clinical presentations of adult aortic coarctation revealed only few reports of acute compressive myelopathy due to spinal epidural collateral vessels. Further, presentation at such a late age has not been reported before. In the present case, apart from a hypertrophied anterior spinal artery and perispinal collaterals, an anterior epidural hematoma was an additional important factor in the causation of myelopathy.

Transcatheter management of adult aortic coarctation with "Railway" technique

Endografting for atretic coarctation is technically feasible to avoid the risks of open surgery. It requires a strategic and structured endovascular approach such as the "Railway" technique for safe and successful restructuring of complete aortic atresia and avoiding rupture or bleeding.

CT evaluation of unrepaired/incidental congenital cardiovascular diseases in adults

Congenital heart disease (CHD) affects approximately one million people in the USA with the number increasing by 5% each year. Patients are usually both diagnosed and treated in infancy, however many of them may have subclinical CHD that remains undiagnosed until late adulthood. Patients with complex CHD tend to be symptomatic and are diagnosed at a younger age than those with a single defect. CHDs can be divided into three categories, including cardiac, great vessels and coronary artery anomalies. Recent advances in computed tomography (CT) technology with faster acquisition time and improved spatial resolution allow for detailed evaluation of cardiac morphology and function. The concomitant increased utilization of CT has simultaneously led to more sensitive detection and more thorough diagnosis of CHD. Recognition of and understanding the imaging attributes specific to each anomaly is important for radiologists in order to make a correct and definite diagnosis. This article reviews the spectrum of CHDs, which persist into adulthood that may be encountered by radiologists on CT.

Coarctation of Aorta and Post-Stenotic Dissecting Aortic Aneurysm Successfully Treated with Endovascular Stent

Coarctation associated with a dissected aneurysm is uncommon and has an incidence of less than 1%. There are few reports describing treatment of this condition with stent graft. Challenging as it may be, endovascular treatment of complex cases has become the preferred modality especially when the anatomy is amenable. We describe the case of a 36-year old male, who suffered a car accident and was diagnosed with acute type B aortic dissection (ATBAD). CT-scan revealed a coarctation associated with a large dissected aneurysm (11cm). Complexity of pathology and high risk of rupture required immediate intervention. Open repair necessitates extensive surgery with a considerable risk of morbidity and mortality. We decided to perform an endovascular repair and subsequentially the patient was successfully treated with stent graft deployment, showing durable early-midterm results. Patient remains asymptomatic to this day and CT-scan at 3-year follow-up revealed a reduced and thrombosed aneurysm.

Patient-specific three-dimensional aortic arch modeling for automatic measurements: clinical validation in aortic coarctation

AIM

A validated algorithm for automatic aortic arch measurements in aortic coarctation (CoA) patients could standardize procedures for clinical planning.

METHODS

The model-based assessment of the aortic arch anatomy consisted of three steps: first, machine-learning-based algorithms were trained on 212 three-dimensional magnetic resonance (MR) data to automatically allocate the aortic arch position in patients and segment the aortic arch; second, for each CoA patient (N = 33), the min/max aortic arch diameters were measured using the proposed software, manually and automatically, from noncontrast-enhanced three-dimensional steady-state free precession MRI sequence at five selected sites and compared ('internal comparison' referring to the same environment); third, moreover, the same min/max aortic arch diameters were compared, obtaining them independently, manually from common MR management software (MR Viewforum) and automatically from the model (external comparison). The measured sites were: aortic sinus, sino-tubular junction, mid-ascending aorta, transverse arch and thoracoabdominal aorta at the level of the diaphragm.

RESULTS

Manual and software-assisted measurements showed a good agreement: the difference between diameter measurements was not statistically significant (at α = 0.05), with only one exception, for both internal and external comparison. A high coefficient of correlation was attained for both maximum and minimum diameters in each site (for internal comparison, R > 0.73 for every site, with P < 2 × 10). Notably, in tricuspid aortic valve patients external comparison showed no statistically significant difference at any measurement sites.

CONCLUSION

The automatically derived aortic arch model, starting from three-dimensional MR images, could be a support to take the measurements in CoA patients and to quickly provide a patient-specific model of aortic arch anomalies.

Native aortic coarctation stenting in patients ≥ 46 years old

Introduction

Stent implantation is an effective therapy for aortic coarctation (CoA) in adolescents and adults.

Aim

To present a unique group of patients with native coarctation of the aorta older than or equal to 46 years treated with bare metal or covered stents.

Material and methods

Since 2002 we have performed stent implantations by applying bare metal stents or covered stents using femoral access in 24 patients aged 46 and older.

Results

We used the Mullins technique in all cases, implanting different stents: Palmaz, Cheatham-Platinum (CP), covered CP or Andrastents XL/XXL. Twenty-one procedures were elective and 3 were urgent. Eighteen bare metal stents (2 stents in one patient) and 7 covered stents were used. All procedures were effective (CoA gradient reduced < 20 mm Hg), despite 2 migrations of bare metal stents. Mean gradient was reduced from 50.6 ±15.3 to 6.8 ±6.5 mm Hg (p < 0.001) and mean lumen diameter of stenosed aorta increased from 5.5 ±2.5 to 14.9 ±5.2 mm (p < 0.001). One special case is discussed – a 49-year-old man with end staged heart failure and severe CoA, who underwent a rescue procedure with a bare metal stent. One serious complication – stroke of the central nervous system – was observed in a 53-year-old woman during covered stent implantation (symptoms resolved during rehabilitation process).

Conclusions

Stent implantation of native coarctation of the aorta is also a safe procedure in the eldest patients and is associated with persistent relief of aortic obstruction.

Staged open repair for a complex adult aortic coarctation

We describe a two-stage open repair for a complex aortic coarctation in an adult. A total arch replacement with an elephant trunk was performed via a median sternotomy followed in 10 days by a replacement of the descending aorta through a left thoracotomy.

Preoperative Evaluation and Endovascular Procedure of Intraoperative Aneurysm Rupture During Thoracic Endovascular Aortic Repair

Thoracic aortic aneurysms are now routinely repaired with endovascular repair if anatomically feasible because of advantages in safety and recovery. However, intraoperative aneurysm rupture is a severe complication which may have an adverse effect on the outcome of treatment. Comprehensive preoperative assessment and considerate treatment are keys to success of endovascular aneurysm repair, especially during unexpected circumstances. Few cases have reported on intraoperative aortic rupture, which were successfully managed by endovascular treatment. Here, we present a rare case of an intraoperative aneurysm rupture during endovascular repair of thoracic aortic aneurysm with narrow neck and angulated aorta arch (coarctation-associated aneurysm), which was successfully treated using double access route approach and iliac limbs of infrarenal devices.

LEVEL OF EVIDENCE

Level 5.

Thoracic Stent Graft Implantation for Aortic Coarctation with Patent Ductus Arteriosus via Retroperitoneal Iliac Approach in the Presence of Small Sized Femoral Artery

Endovascular stent graft implantation is a favorable method for complex aortic coarctation accompanied by patent ductus arteriosus. Herein, an 18-year-old woman with complex aortic coarctation and patent ductus arteriosus was successfully treated by endovascular thoracic stent graft via retroperitoneal approach. The reason for retroperitoneal iliac approach was small sized common femoral arteries which were not suitable for stent graft passage. This case is the first aortic coarctation plus patent ductus arteriosus case described in the literature which is treated by endovascular thoracic stent graft via retroperitoneal approach.

CT and MRI of aortic coarctation: pre- and postsurgical findings

OBJECTIVE. The purpose of this article is to summarize the roles of CT and MRI in the diagnosis and follow-up of patients with aortic coarctation. CONCLUSION. Aortic coarctation is a common congenital heart disease accounting for approximately 6-8% of congenital heart defects. Despite its deceptively simple anatomic presentation, it is a complex medical problem with several associated anatomic and physiologic abnormalities. CT and MRI may provide very accurate information of the coarctation anatomy and other associated cardiac abnormalities.

MRI in adult patients with aortic coarctation: diagnosis and follow-up

Aortic coarctation is a disease that usually presents in infancy; however, a proportion of patients present for the first time in adulthood. These lesions generally require repair with either surgery or interventional techniques. The success of these techniques means that increasing numbers of patients are presenting for follow-up imaging in adulthood, whether their coarctation was initially repaired in infancy or as adults. Thus, the adult presenting to the radiologist for assessment of possible coarctation or follow-up of coarctation repair is not an uncommon scenario. In this review, we present details of the MRI protocols and MRI findings in these patients so that a confident and accurate assessment can be made.

Open repair of adult aortic coarctation mostly by a resection and graft replacement technique

BACKGROUND

We report on our experience with treatment of adults requiring de novo or redo open aortic coarctation repair mostly by a resection and interposition graft technique.

METHODS

We retrospectively reviewed all patients older than 16 years requiring open repair of aortic coarctation. Indications for repair, operative details, and outcomes were analyzed.

RESULTS

Between 1996 and 2011, we treated 29 adult aortic coarctation patients with open repair. The mean age was 42 years (range, 17-69 years), and there were 15 men. Nine patients had previous repair with recurrence; the remaining 20 had native coarctation. Thoracic aortic aneurysms were present in 22 patients (76%), ranging in size from 3.0 to 9.6 cm (mean, 4.8 cm). Four patients had intercostal artery aneurysms (range, 1.0-2.5 cm), four had left subclavian artery aneurysms, and four had ascending/arch aneurysms. The most common repair was resection of aortic coarctation with interposition graft replacement (93%). Two patients without aneurysm had bypasses from the proximal descending thoracic aorta to the infrarenal aorta without aortic resection. There was no in-hospital mortality, stroke, or paraplegia. Long-term survival was 89% during a median follow-up of 81 months (interquartile range, 47-118 months), with no patient requiring reoperation on the repaired segment.

CONCLUSIONS

Open repair of native and recurrent adult aortic coarctation has acceptable morbidity and low mortality. Especially in patients with concomitant aneurysm, resection with interposition graft replacement provides a safe and durable repair option.

[Pregnancy-related cardiac problems]

All women of child-bearing age suffering from congenital cardiac valve malformations or acquired valvular disease, pulmonary hypertension or arterial hypertension and who are at risk for coronary heart disease should receive early counseling and optimal treatment before pregnancy. They should be treated by an interdisciplinary team composed of gynecologists, cardiologists, geneticists and, if necessary, cardiac surgeons. This interdisciplinary approach should be used for all pregnant women with cardiac disease in order to minimize maternal and fetal mortality. As physicians will only rarely be confronted with such critically ill patients, guidelines and access to worldwide information from databanks are particularly important (http://www.safetus.com und http://www.emryotox.de).

Ruptured sinus of valsalva aneurysm and coarctation of aorta in a woman at early postpartum period

Coarctation of aorta and sinus of Valsalva aneurysm are frequently missed congenital cardiac defects that their diagnosis might be delayed. To our knowledge, coincidence of these cardiac defects is unusual and has not been reported in the literature before. Here, we present a patient with coarctation of aorta and ruptured noncoronary sinus of Valsalva aneurysm leading to aorto-right atrial fistula in the early postpartum period and our management of this unusual case.

Endovascular therapy in patients with genetically triggered thoracic aortic disease: applications and short- and mid-term outcomes

OBJECTIVES

For patients with genetically triggered thoracic aortic disease, the morbidity and mortality associated with reoperation are high, making endovascular treatment an appealing option. We evaluated the short- and mid-term outcomes of different applications of endovascular intervention in such patients.

METHODS

Between January 2003 and April 2013, 60 patients received endovascular or hybrid treatment for genetically triggered thoracic aortic disease. The inclusion criteria were based on those devised by the National Registry of Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions. We included patients with thoracic aneurysm or dissection not due to trauma in a patient aged ≤50 years (n = 30), bicuspid aortic valve (BAV) and coarctation (n = 11), Marfan syndrome (n = 10), BAV with thoracic aneurysm (n = 4), Loeys-Dietz syndrome (n = 3), familial thoracic aneurysm or dissection (n = 3) and genetic mutations (n = 2). Some patients met more than one inclusion criterion. Forty-one (68.3%) patients were treated with only endovascular stent grafting. Nineteen (31.7%) patients underwent a hybrid procedure with open proximal or total arch replacement and concomitant endovascular stenting of the aortic arch or the descending thoracic aorta. Twenty-nine (48.3%) had previous cardiovascular operations (mean ± SD, 1.9 ± 1.4) before undergoing hybrid or endovascular therapy. The median follow-up was 2.3 years (interquartile interval 25-75%, 1.4-4.6 years).

RESULTS

The technical success rate was 100%. In-hospital mortality was 3.3% (n = 2) and neurological events occurred in 2 patients; 1 (1.6%) had a stroke and 1 (1.6%) suffered paraparesis with partial recovery. Fifteen repeat open or endovascular interventions were required in 10 surviving patients (17.2%). Overall survival during follow-up was 94.8% (55/58).

CONCLUSIONS

Endovascular technology can be helpful in treating selected young patients with genetically triggered thoracic aortic disease. Long-term studies and further evolution of endovascular technology will be necessary for it to be incorporated into the armamentarium of surgical options for this challenging patient population.

An adolescent patient with coarctation of aorta treated with self-expandable nitinol stent

Transcatheter treatment of aortic coarctation, with balloon angioplasty or stent implantation, is now an acceptable alternative to surgical repair. However these procedures may result in complications, such as vascular wall injury and re-stenosis of the lesion. A nitinol self-expandable stent, when deployed at the coarctation site, produces low constant radial force, which may result in a gradual widening of the stenotic lesion leaving less tissue injury ('stretching rather than tearing'). For an adolescent with a native aortic coarctation, a self-expandable stent of 20 mm diameter was inserted at the discrete stenotic lesion of 5 mm diameter without previous balloon dilatation procedure. No further balloon dilatation was done immediately after the stent insertion. With the self-expandable stent only, the stenosis of the lesion was partially relieved immediately after the stent deployment. Over several months after the stent insertion, gradual further widening of the stent waist to an acceptable dimension was observed.

Keepers at the final gates: regulatory complexes and gating of the proteasome channel

The proteolytic active sites of the 26S proteasome are sequestered within the central chamber of its 20S catalytic core particle. Access to this chamber is through a narrow channel defined by the outer alpha subunits. Free proteasome 20S core particles are found in an autoinhibited state in which the N-termini of neighboring alpha subunits are anchored by an intricate lattice of interactions blocking access to the channel. Entry of substrates into proteasomes can be enhanced by attachment of activators or regulatory particles. An important part of this activation is channel gating; regulatory particles rearrange the blocking residues to form an open pore and promote substrate entry into the proteolytic chamber. Interestingly, some substrates can open the entrance themselves and thus facilitate their own destruction. In this review, we will discuss the mechanisms proposed for channel gating and the interactions required to maintain stable closed and open conformations.